The present invention relates generally to imprint lithography. More particularly, the present invention is directed to a method, system and holder to transfer templates during imprint lithography processes.
Micro-fabrication techniques can produce structures having features on the order of nanometers. Micro-fabrication is used in a wide variety of applications, such as the manufacturing of integrated circuits (i.e. semiconductor processing), biotechnology, optical technology, mechanical systems, and micro-electro-mechanical systems (xe2x80x9cMEMSxe2x80x9d).
Imprint lithography is a type of micro-fabrication technique that is becoming increasingly important in semiconductor processing and other applications. Imprint lithography provides greater process control and reduction of the minimum feature dimension of the structures formed. This in turn provides higher production yields and more integrated circuits per wafer, for example.
Micro-fabrication can be used to form a relief image on a substrate, such as a semiconductor wafer. The substrate typically has a transfer layer that is coated with a thin layer of polymerizable fluid, thermoplastic, or other imprint material capable of being formed (i.e. molded or imprinted) into a desired structure. A mold with a relief structure makes mechanical contact with the substrate and the polymerizable fluid or other imprint material fills the relief structure of the mold. The polymerizable fluid is then polymerized to form the desired structure on the transfer layer, which is complimentary to the relief structure of the mold. The transfer layer and the solidified polymeric material can then be etched to form a relief image in the transfer layer, or coated with a thin-film layer of other material, for example.
Imprint lithography systems often use an imprint head with a mold, also called a template, which can be installed and removed from the imprint head. This allows the imprint lithography system to be used to imprint different patterns. In this manner, the imprint lithography system can be used to fabricate various types of circuits or other devices, or imprint various structures on a substrate.
To ensure high resolution imprinting it is generally desirable to minimize handling of the template in order to avoid damage to the template and contamination to the template and imprint lithography system with dust or other particulates. To that end, there is a need to store, load, and unload templates in a manner that avoids physical damage to the relief pattern of the mold and contamination to the template and imprint lithography system.
The present invention is directed to techniques for handling templates during imprint lithography processes to avoid damage and/or contamination to the mold pattern on the imprint face of the template. To that end, a method for handling a template, having a patterned mold thereon, in an imprint lithography system having a motion stage with a chucking device coupled thereto, includes providing the template into a template transfer holder. The template transfer holder includes a side coupled to the motion stage and support members extending from the side. The template is disposed within the template transfer holder so as to have the patterned mold facing the side and spaced-apart therefrom. Relative movement is created between the motion stage and an imprint head to place the template transfer holder and the imprint head in superimposition. The template is removed from the template transfer holder and suspended above the wafer chuck by the imprint head. In another embodiment a system and a template holder are described that facilitate the method. These and other embodiments are described more fully below.